Adjustable wrench



" J. PEHRSSON ADJUSTABLE WRENCH Filed July 14, 1.933

wlml/wzymm/l/l/llmm'arm fiepito 3 Patented Sept. 3, 1935 ADJUSTABLEWRENCH Johan Pehrsson, skillingaryd sweden Application July 14, 1933,Serial No. 680,453 In Sweden August 11, 1932 4 Claims.

glation to the former and slidably in the handle .m'ember or, in a headprovided thereon and ,adapted to support the fixed jaw, an adjusting.rnember being rotatably mounted in, or on, the handle, or head, suchadjusting member coacting with the adjustablejaw for the purpose ofdisplacement of the same in relation to the fixed 10119.; W l V 'I hemain object of the invention is to construct the adjusting member insuch a manner that it will be self-locking, so that the adjustment andlocking of the adjustable jaw may be performed by means of one singlemanual operation.- For this purpose, the. adjusting member isconstructed in the form or a cam disc having a helically shaped workingface, the pitch of thehelixoi which being everywhere smaller than theself-locking friction angle. By means of a suitable transmission member,preferably a 1ever, the said cam disc coacts with the adjust- ;able jawand the construction is of such a kind that the possibilities for a deadmotion are practicallyeliminated.

, Hence, itwill be possible, from agreater distance, or gap, between thejaws, by means of a simple manipulation to adjust the wrench tothedesired grip rigidly around the nut, or the like, and this rigid gripis not changed or lost, due to torsional forces arising when turning thenut..

The invention hasalso for its purpose to sim- ,plify the mechanicalconstruction of the means required in such a manner that itmay beapplied to practice, without the requirement of any special mechanicalexactness.

The invention is illustrated in the accompany- .ingdrawingwhich shows anumber of embodimerits thereof. In the drawing:- i

i Fig. 1 shows the exterior of the wrench seen winelevation, and a aFig. 2, in a similar manner, shows the head end of the wrench, theinterior mechanical parts of which: are shown in dotted lines. 1 .Fig. 3is a sectionat the line A-B in Fig. 2,

.and

Fig. 4 is a section at the line C-D in the same figure. a a

Fig. 5 is a detail section of a connection rivet atthelinelE -F in Fig.1.

Fig. 6 shows a modification of the adjusting means seen in elevation,and

Fig. 7 is asection at the line G-I-Iin Fig.6.

Fig. 8, in the same manner .as Fig. 6, shows another modificationof theadjusting members,

and

Fig. 9 is a section at the line 1- in Fig. 8.

i In the customary manner, the wrench ,(Fig. 1) consists of a handle Iprovided with a head 2 supporting and embracing the adjusting means,such head being rigidly connected with the fixed jaw 3, an adjustablejaw 4 being slidably mounted in the head 2 in relation to the fixed jaw3. The adjustment and locking, of the adjustable jaw areafiected andcontrolled by the adjusting means whichare actuated by means of a lever5 rotatably mounted exteriorly on the wrench head2 and shaped so as toform a thumb piece. In the embodiment according to Figs. 1-3, theadjustable jaw is supposed to be slidable ma direction substantiallyperpendicular to. the direction of length of the handle I, but naturallyit might have been mounted so as to slide substantially parallel to thedirection of length of the handle, in case the fixed jaw takes acorresponding position on the wrench head. Hence, the invention is notlimited to wrenches havin their nut gaps positioned substantiallyTtransversely to the'handle only.

At the one side, i. e. the upper side in Fig. 3,

{the wrench head is provided with arecess for accommodation of theadjusting means, and such means are mounted in a protected positioncoveredby a side plate 8 .(Figs. 3 and 4) riveted to the wrench head.One of the rivets 1 serves as a'pivot for an adjusting lever 8, whichina. suit able manner adapted as far as possible to prevent dead motion ishingedly connected withthe adjustable jaw l slidably mounted in suitableguides in the wrench head 2 and the side. plate {5. In constructionalrespect the said hingeconn'ec tion may be brought about ,in manydifferent ways, for instance by means ofan' intermediate link member,but theconstruction shown in the drawing can be considered simpler andmore enicient in practice. According to the drawingthe hinge-connectionis simply performedby means of a tempered tooth 8 provided at the freeend of the lever B and engaging a corresponding recess in theguide'fiange of the adjustable jaw 4, the width of the tooth being sodimensioned that the recess is substantially completely filled up, butthe depth of the recess is so much greater than the height of the tooththat the latter cannot be jammed in the former in any position. It is tobe noted that this construction is intended for obtaining ahinge-connection only, and it is not to Y'UN ED STATES PATENT OFFICE:

be confused for a toothed rack connection intended for transforming arotational movement into a reciprocating one, or vice versa.

According to the invention, the means for transforming the rotationalmovement of the thumb piece lever 5 into a reciprocating movement of theadjustable jaw 4 consists of a helical cam disc member connected withsaid lever and coactingwith the adjusting lever B, and in all of theembodiments shown the said cam member is fixedly connected with theshaft 9 of the thumb piece lever, said shaft being rotatably mounted inthe wrench head 2.

In the embodiment according to Figs. l-4, the outer circumference of thehelical cam disc is adapted to actuate an abutment 8 on the lever 8 foradjustment of the jaws in a direction towards each other, whereas theadjustment of the jaws in a direction from each other is performed bymeans of a spring II inserted between a seat on the adjustable jaw & anda corresponding eat means provided on a connection rivet l bee-Fig.- 5between the wrenchhead 2 and the side plate 6. This spring, acting as apressure spring, is mounted in a corresponding recess in the guides forthe adjustable jaw in the wrench head; 7

embodiment of this kind is permissible without inconveniences, as it isthe possibilities or dead motion of the jaws in a direction from eachother; which are of any influence in practhee-when using the wrenchonly, whereas the possibilities for dead motion of-the jaws in theopposite direction are of no consequence. In case it its-desired thatthe possibilities for dead moshall-be'prevented in both directions, theembodiments described inthe following might be adheredto.

In the; embodiment according to Figs. 6 and 7, the spring- H issuperfluous, and, besides of the circumferential edge It? coacting withthe abutment-Wthe cam disc member HT is also provided 'with an innerguiding edge Hl adapted to coact abutment pin l2 fixedly mounted on thelever-1'8, the positionof which in relation to the discW'being-positively determined thereby.

In the embodiment accordingto-Figs. 8 and 9, the position of the lever 8in relation to the cam disc member is positively determined in a similarmanner in that the cam disc is provided with a helically shaped guidegroove I3 straddling a pin H' rigidly attached to the lever 8. In thisinstance there is no necessity for providing the lever with any abutmentmeans coacting with the circumference of the cam disc, and saidcircumference may be circular, as indicated in Fig. 8.

In all of the embodiments, at least the helical working face of the cammember performing the advance of the jaws towards each other shall haveso small a pitch that it is everywhere smaller than the friction angle,and thereby the adjusting means will be self-locking. In the embodimentaccording to Figs. 6-9, the working face of the cam member performingthe adjustment of the jaws in a direction from each other need not havesuch a small pitch for a reliable functioning of the wrench (forperforming an efficient grip on the nut, or the like), but preferablyboth of the working faces have the same pitch, and pref- 'erably themeans coacting with the working faces (the distance between the abutment8 and the pin I2 in Fig. 6, and the diameter of the pin l4 Fig. 8) areconstructed in such a manner that the possibilities for a dead motionare prevented in both directions.

As will be understood from Fig. 2, one of the connection rivets 1 may beused as an abutment coacting with the lever 8 for limiting the relativeslidability of the jaws in a direction from each other.

Naturally, all of the constructional members adapted for the adjustmentought to be made from hard steel for the purpose of reduction of thewear, and since the interior space between the wrench head 2 and theside plate 6 is preferably open at least towards one side (compare Fig.4), a lubrication of the said members may easily be performed.

What I claim and desire to secure by Letters Patent is:-

1. An adjustable wrench, comprising a wrench head, a handle memberextending from said head and rigidly connected therewith, a fixed wrenchjaw connected with the wrench head and-extending therefrom in anopposite direction to the handle, said head having a cavity providedtherein, a cam disc member rotatably mounted within said cavity andprovided with a helically shaped working face the pitch of whichiseverywhere smaller than the selflcckingfriction angle, an adjustablewrench jaw slidably mounted in-the wrench head parallel to the fixedjaw, for bodily linear movement transversely of the wrench head andrelative to said fixed jaw, and an intermediate transmission memberprovided between the adjustable jaw and the cam disc member, saidtransmission member and saidadjustable jaw having loosely contactingcooperable members whereby the transmission member can impart liftingmotion to said adjustable jaw, means for returning the jaw to its restposition, and a bearing surface on said transmission member andcontacting with the helical work-ing face of said cam disc member andadapted to receive motion therefrom.

2. An adjustable wrench according to claim 1, in which the intermediatetransmission member consists of aone-armedlever pivotal-1y mounted atitsone end to the'handle member and engaging a recess in the adjustable jawat the other, the intermediate portion of'sa'id lever being positionedin contact with the working face ofth'e cam disc member.

3.'An adjustable wrench, comprising a'wreneh head,- a handle memberextending-from said and rigidly connected therewith,- afixed wrench jawconnected with the wrench head and eitendin-g therefromin anoppositedirection to the handle; a cam disc member rotatably mounted in thewrench head and provided with a'heli-cali'y shaped working face thepitch of which is everywhere smaller than the self locking frictionafigle, a lever means mounted'pi'votally irrthe wrench head and providedwith an" abutment means coactingwith'the said working face or the camdisc member for adjustment of the adjustable wrench jaw in a directiontowards theflxed one, a-tooth means providedat one end or the said levermeans and engaging a-correspendiiig recess in the adjustable jaw, andmeans for adjus-tment of the adjustable jawin a direction away fromthefixed one. A

4. An adjustable wrench according to claim 3, in which the adjustablewrench jaw is springactu'ated in a direction from the fix'edone'.

j JGHAN PE H RS

